Auto Attendant; an application designed to permit a switchboard attendant to efficiently distribute calls received by an enterprise.

Automatic call distribution; a call routing application whose primary function is to deliver calls that arrive at an enterprise to an available user. This application is commonly used to deliver calls to call centers or groups of attendants.

Admission Confirm; an H.323 gatekeeper sends this RAS message when it permits an H.323 endpoint to make a call.

Acknowledgement.

A type of conference in which a controlling station manually adds conferees one at a time. Contrast with Meet-Me conference.

Advanced Encryption Standard Counter Mode; an encryption algorithm.

Automatic Location Identification; information about the physical location of a caller that emergency response centers use when handling E911 calls.

A Cisco IP Voice Media Streaming App device that plays various pre-recorded announcements and tones to a single party, a conference, or an MTP.

American National Standards Institute; an American organization chartered with the development of standards in the United States.

Application protocol data unit; in QSIG, a message with associated parameters that is sent from the feature layer in one PINX to the feature layer in another PINX by tunneling the message in the QSIG generic functional protocol.

Application programming interface; usually a set of libraries with accompanying header files that application programmers can use in their programs to interact with a third-party application.

Admission Reject; an H.323 gatekeeper sends this RAS message when it denies an H.323 endpoint’s request to place a call.

Admission Request; H.323 endpoints that rely on a gatekeeper to route their calls send this RAS message, which requests permission from the gatekeeper for the endpoint to place a call.

Administrative Reporting Tool; a web-based application used to generate various reports about the CallManager system.

Abstract Syntax Notation One; an ITU-T language designed for the description of data types. H.323 defines certain parts of certain messages in ASN.1.

Active Server Page; a web page that uses ActiveX scripting to dynamically control the content of the web page. Cisco CallManager Administration relies on Active Server Pages.

Admin. Serviceability Tool; a CallManager Serviceability tool that can be used to view performance information for the CallManager cluster.

Audit Connection; an MGCP message that the call agent sends to the gateway to audit the specified connection on an endpoint.

Audit Endpoint; an MGCP message that the call agent sends to the gateway to audit a specified gateway.

A security process whereby one network component (for instance, CallManager) validates the identity of another, such as a gateway or IP phone. Authentication can be one-way, in which case one component can trust the identity of the other but not vice versa, or two-way, in which case both components can be confident as to the identities of each other.

A security process whereby a network component defines what types of services that an authenticated component can access. For example, you can configure CallManager routing to provide long distance calls for certain valid users but not for other valid users.

Advanced Video Coding.

Cisco Architecture for Voice, Video, and Integrated Data; a suite of applications that is designed to handle enterprise voice networks and which processes user calls over an enterprise’s IP network.

Back-to-back user agent; a call agent that maintains two independent sessions, one from the originator to the call agent and one from the call agent to the target.

Bearer channel; one of 23 or 30 timeslots of information that can carry a user’s voice or data content over an ISDN interface. See also D-channel.

The practice of passing signaling information from PSTN ports transparently through a gateway to a call agent, rather than relying on the gateway to process the signaling information itself.

A measurement of the amount of data per unit of time that a communications interface can send or receive.

Bulk Administration Tool; a web-based application used to bulk-add, bulk-update, or bulk-delete large numbers of devices and users in the CallManager database.

Bandwidth Confirm; an H.323 gatekeeper sends this RAS message when it honors an H.323 endpoint’s request to change the bandwidth of the media stream that the endpoint is using.

Busy hour call attempts; a call attempt is a transaction that begins when a caller goes off-hook and immediately dials four digits. The transaction completes when the originator returns to an idle state, whether call setup completed to the target phone or an error condition was encountered. BHCA is the number of these transactions, at a sustained rate, that a CallManager or cluster of CallManagers can process within one hour. However, Cisco bases CallManager performance metrics on BHCC, a statistic that focuses of the number of successful calls.

Busy hour call completion; call completion is a transaction that begins when a caller goes off-hook, immediately dials four digits, and rings a target phone, which immediately answers. The transaction completes when the endpoints negotiate and exchange media, terminate their session, and return to the idle state. BHCC is the number of these transactions that a CallManager or cluster of CallManagers can process in one hour, with the assumption that all call transactions are evenly spaced.

Cards that are the width of the chassis that they are going into and contain the DSPs for transcoding, conferencing, and media termination. See also VICs.

Busy Lamp Field; an indicator at a station that displays the busy or idle status of other users in the enterprise.

Basic Rate Interface; a version of ISDN designed for phones that uses two B-channels for media and one D-channel for signaling.

See shared line appearance.

Bandwidth Reject; an H.323 gatekeeper sends this RAS message when it denies an H.323 endpoint’s request to change the bandwidth of the media stream that the endpoint is using.

Bandwidth Request; a gatekeeper-enabled H.323 endpoint sends this RAS message when it wants to change the codec (and thus the bandwidth) that it is using for a particular media session.

Berkeley Software Distribution; an open source code distribution originated at the University of California at Berkeley.

A DSP inside Cisco IP Phones that acts as a small conference bridge.

Mechanisms that prevent an IP network from becoming clogged with voice and video traffic to the point of unusability by rejecting new call attempts when the network path is saturated with calls. CallManager currently supports two forms of CAC: gatekeeper-controlled and locations-based.

A configuration of CallManager whereby the administrator makes it appear as if the same line appearance occurs multiple times on an individual phone.

Mechanisms that allow CallManager to intelligently route a single call to several devices—either simultaneously or serially. Route lists and hunt lists are call hunting constructs.

A value appearing in call detail records (CDR), unique among all CallManager nodes in a cluster, that identifies each participant in a call.

The process by which a Cisco IP Communications network maintains the media exchange of a call in progress when a network error or server failure interrupts the signaling and media control for the call.

The calling number of a station that places a call.

Along with partitions, a call routing concept that allows CallManager to provide individualized routing to users for purposes of routing by class of calling user, geographic location, or organization.

Centralized Automatic Message Accounting; a system in a central location capable of collecting data, usually call accounting-related, on behalf of multiple switches.

Channel Associated Signaling; a scheme for transmission of call signaling information that relies on interleaving the call signaling within the media information that the interface transmits.

Cisco CallManager; a Cisco IP Communications service whose primary function is the control and routing of calls from voice-enabled IP devices.

Common Channel Signaling; in circuit-switched communications, a system in which one channel of a multiple-channel link is reserved to handle the call signaling for all other channels, which can then be dedicated solely to media.

Cisco Discovery Protocol; a device discovery protocol that runs on Cisco devices and allows devices to advertise their existence to other devices on a LAN or WAN.

Called party number.

Call detail record; a record that CallManager logs after a call completes to permit billing or auditing of system use.

The grouping together of call detail records (CDR) and call management records (CMR).

A single location where CallManager stores all CDR data, either in flat files or in a common CDR database.

A cluster deployment model whereby a cluster in a campus provides IP telephony service across the IP WAN for phones and gateways in branch offices that lack a CallManager.

Call Forward All; a CallManager feature that allows all calls placed to a given directory number to be forwarded to a different directory number.

Call Forward Busy; a CallManager feature that allows calls placed to a given directory number to be forwarded in the event that the directory number is busy.

Call Forward No Answer; a CallManager feature that allows calls placed to a given directory number to be forwarded in the event that they are not answered.

Call Forward No Coverage; a CallManager feature that allows calls that have forwarded to a hunt list with personal final forwarding enabled to route to the CFNC destination configured on the original endpoint if no endpoint in the hunt list accepts the forwarded call.

Call Forward on Failure; a CallManager feature that allows calls to a directory number associated with a CTI application to forward when the CTI application is no longer associated with CallManager because of a failure such as an application server crash or disconnected link.

Calling party number.

Common Intermediate Format.

A process of completing calls whereby a call agent manages the transport of the media from one endpoint to another through commands to switch cards that form an actual end-to-end analog or digital circuit.

A Cisco-certified Windows 2000 server that is running CallManager software.

A voice mail system that integrates with CallManager. Formerly known as Active Voice.

A family of web-based products used to manage Cisco enterprise networks and devices.

A switch in a national telephone system operated by a local telephone company. Class 5 switches directly handle residential and commercial subscribers.

Command line interface; an interface to Cisco switches and routers running the IOS operating system in which a user types text commands to provision a device.

The loss of speech during the initial moments of a conversation due to delay in setting up an end-to-end media path after the called party answers.

Calling line ID; the calling number of a station that is placing a call.

A system of resolving conflicts between multiple matched dial patterns that prioritizes patterns of lower expressivity (that is, patterns that match the fewest number of input dial strings) over patterns of greater expressivity (patterns that match a greater number of input dial strings). With closest match routing, the dial string 1234 would select pattern 1X34 instead of 12XX in a configuration that included both patterns.

A process by which CallManager nodes cooperatively processes an enterprise’s calls with such tight integration that users cannot detect which CallManager nodes are processing their calls. Clustering relies on direct communication among CallManager nodes in a cluster.

Separation of CallManager cluster members into different geographic areas.

Common Management Framework; the Cisco management foundation on which CiscoWorks network management application suites run.

Cisco Messaging Interface; a Windows 2000 service that is part of Cisco IP Communications and that coordinates SMDI communications with legacy voice mail systems.

Call management record; also known as a diagnostic record, a record that CallManager logs that provides information about the media session on which a device participated.

Calling party name identification; a feature that permits CallManager to present the calling user’s display name to the called party.

Central office; a switch in the PSTN, usually Class 5, that handles calls on behalf of residential and commercial subscribers.

Coder-decoder; a media-encoding scheme by which an end device encodes speech or visual information into a digital representation for transmission across a media connection. It decodes the digital representation into speech or visual information for playback by the recipient.

Component Object Model; a Microsoft framework used in many companies’ applications that is designed to permit the interoperation of software objects running in separate tasks in a computer network.

Background noise that is meant to make the user feel more comfortable that the call is still active while the endpoint with which he or she is conversing is suppressing audio. Also called white noise or background noise.

In the context of SNMP, a relationship between an agent and a set of SNMP managers that defines security characteristics.

A conference controller is the user who initiates a conference. For Ad Hoc conferences, the conference controller calls each conference participant and individually connects each participant to the conference. For Meet-Me conferences, the conference controller sets up the directory number that conference participants dial into.

A media device that mixes multiple signals from different stations or gateways and sends the combined signals to all the conference participants.

Class of service; a method of classifying the data that a network routes to provide preferential packet routing treatment to data related to certain types of media: voice, data, and video, for example.

Central processing unit; the chip or chips inside a computer that execute the instructions that permit applications to function.

Create Connection; an MGCP message the call agent sends to gateway to create a new connection on an endpoint.

Comma-separated value; a type of file in which commas are used to separate individual fields of a complex data record and new lines indicate the end of an individual record.

Computer Telephone Integration or Computer Telephony Interface; for the purposes of this book, CTI most commonly means Computer Telephony Interface. This is an interface exported by CallManager that allows application developers to create programs that work with the telephone system.

Data channel; one timeslot on an ISDN interface that is dedicated to handling the call signaling related to the bearer channels that the interface manages. See also.

Database Layer; a set of software components that provide a programming interface to the SQL database containing all the CallManager configuration information.

Disengage Confirm; an H.323 gatekeeper sends this RAS message when it wants to honor an H.323 endpoint’s request to terminate a call.

A Cisco gatekeeper feature that, when configured, instructs the gatekeeper to look for endpoints that have registered with the specified technology prefix and choose one of these endpoints to route the call to.

Data Encryption Standard; an encryption algorithm.

Dynamic Host Control Protocol; a network service whose primary purpose is to automatically assign IP addresses to new devices that connect or existing devices that reconnect to the network.

See CMR.

Any CallManager setting that permits CallManager to modify the calling or called number as the call is being established.

Direct Inward Dial; a type of central office trunk that provides additional routing information on incoming calls. This allows trunk calls to be routed directly to a specific directory number, instead of being routed to a common attendant.

A CallManager cluster deployment model whereby independent CallManager clusters, possibly gatekeeper-enabled, handle the call routing and call establishment for an enterprise and its branch offices.

Delete Connection; an MGCP message the call agent sends to gateway to delete a connection on the endpoint.

Dynamic link library; a software component used by a larger program that the operating system on which the program runs includes only when the program requires the functionality provided by the software component. Dynamic link libraries allow large programs to use less RAM because they only take up memory when the larger program actually executes them.

Directory number; the numeric address assigned to phones within an enterprise.

Domain Name System; a network service whose primary function is to convert fully qualified domain names (textual) into numeric IP addresses, and vice versa.

Direct Outward Dial; a service that permits a device in the enterprise to place calls directly to the public network.

Denial-of-service attacks; this is a form of attack that can be launched against various network systems. In general, a DoS attack is performed by launching a flood of network requests to a computer, thereby monopolizing its resources.

A formatting convention for an IP address whereby each octet of a 4-octet IP address is converted to a decimal value from 0 to 255 and delimited by periods.

Digital PBX Adapter; Cisco DPAs provide Lucent Octel voice mail integration with CallManager.

Disengage Reject; an H.323 gatekeeper sends this RAS message when it wants to deny an H.323 endpoint’s request to terminate a call.

Disengage Request; a gatekeeper-enabled H.323 endpoint sends this RAS message to the gatekeeper when it wants to terminate a call.

Digital signal processor; a specialized type of CPU used for computationally intensive tasks. CallManager has DSP resources that are typically used to process voice streams. For example, DSPs are used to transcode voice and conference multiple streams.

Direct Station Select; a telephony feature that permits a user to dial a destination by pressing a single button.

Document Type Definition; a specific definition that describes the structure of documents that conform to the Standard Generalized Markup Language (SMGL)—for example, HTML and XML—through the insertion of tags within the documents themselves. Programs interpret the tags and use them to render the document context.

Dual Tone Multifrequency; a common tone signaling method used by touchtone phones in which two pure frequencies are superimposed.

Two-way.

A digital trunk specification that permits the transfer of 2.048 Mbps of information per second.

A fully qualified numeric address for a device attached to a national network. The ITU-T specification E.164 defines the framework in which nations manage their national numbering plans.

To prevent clipping, a set of procedures that establishes a full or partial end-to-end media path between calling and called parties before the called party actually answers.

European Computer Manufacturing Association; an association of European manufacturers that develops standards related to telecommunications.

Event Distribution System; the event distribution of the Cisco Management Framework (CMF).

Enhanced Full Rate; a codec optimized for speech primarily used in digital wireless networks.

Ear and Mouth; an analog trunk interface that carries signaling information over a different pair of wires (called “ear” and “mouth”) than audio information.

An H.323 requirement that endpoints suspend sending media when they receive a mid-call request to select a new codec from an empty list of codecs. CallManager uses this capability to affect features such as hold and transfer.

A device or software application that provides real-time, two-way communication for users.

Emergency Service Number; a numeric address that the North American national network uses to identify emergency response centers.

A framing strategy that groups frames of voice channels into groups of 24.

The process whereby devices on a Cisco IP Communications network seek out backup CallManager nodes if they lose their connection to their primary CallManager.

The process of offering a call to a less-desirable gateway after all desirable gateways have been exhausted.

Also called fast connect; a provision of H.323, version 2, which permits an endpoint to embed media control information in the call signaling phase of a call, thus dramatically speeding up the rate at with an end-to-end media connection can be established.

The ability of a communications system to provide users served by different call agents the same number and quality of features as users served by a single call agent.

A computer system placed at the junction between a private computer network and other computer networks. It is designed to protect users of a private network from users in the other networks.

A method of application control by which the application controls an endpoint as if it were a user at that endpoint.

On a POTS phone, the process of temporarily interrupting the circuit to gain access to network features; on a digital phone, a brief depression of the hookswitch to gain access to network features.

A process whereby a call agent can divert a call from the dialed destination to an alternate destination, either unconditionally or if the called user is busy or does not respond within a specified period of time.

Frames per second.

Signaling bits that synchronize the clocks of the transmitter and receiver.

Full Rate; a codec optimized for speech primarily used in digital wireless networks.

A topology in which every node in a network maintains a communications channel with every other node in a network. CallManager clustering relies on a fully meshed topology.

Foreign Exchange Office; a VoIP gateway providing analog access to central office’s line termination.

Foreign Exchange Station; a VoIP gateway providing analog access to a POTS station.

A simple codec used to encode voice communications that requires 64-kbps bandwidth.

A codec used to encode voice communications that requires either 5- or 6-kbps bandwidth.

A codec used to encode voice communications that requires 8-kbps bandwidth.

An H.323 entity that provides address resolution, controls access to the network, and can terminate calls. In a Cisco IP Communications network, H.323 gatekeepers provide call routing and admissions control functions only.

A device that provides real-time, two-way communications between the packet-based network and other stations on a switched network.

Gatekeeper Confirm; an H.323 gatekeeper sends this RAS message to an H.323 endpoint’s search for gatekeepers on a network if it wants to advertise its existence.

Global call identifier; a common identifier that identifies all calls that are related to each other in some way. Used in CDR data.

A signaling problem that occurs on telephony interfaces when both sides of the wire simultaneously go off-hook and attempt to compete for the same media channel.

Greenwich mean time.

General Regular Expressions Parser; a text-matching capability originally developed for the UNIX operating system. It permits a user to determine whether a particular text string conforms to a user-specified structure.

Gatekeeper Reject; an H.323 gatekeeper sends this RAS message to an H.323 endpoint’s search for gatekeepers on a network if it wants to prevent the H.323 endpoint from registering with it.

A system of call signaling over an analog circuit that relies on both ends temporarily grounding the wires to coordinate seizure of the circuit.

Gatekeeper Request; a gatekeeper-enabled H.323 endpoint sends this RAS message when it needs to find out which gatekeepers it can register with.

Groupe Speciale Mobile; a voice codec commonly used in wireless devices that requires 13-kbps bandwidth.

A protocol that forms the call signaling portion of the ITU-T H.323 protocol.

A protocol that forms the media control portion of the ITU-T H.323 protocol.

An ITU-T recommendation that covers videoconferencing in a circuit-switched environment.

An umbrella ITU-T specification that describes terminals, gateways, and other entities that provide communication services over packet-based networks. It references other specifications for the call signaling, media control, and coding and decoding control specifications.

A protocol that defines feature transparency for the ITU-T H.323 protocol.

In circuit-switched communications, the introduction of unnecessary circuits into an end-to-end signaling and media path, usually as the result of feature operation. In packet-switched communications, the introduction of additional unnecessary signaling or media hops into an end-to-end path, also usually as the result of feature operation.

A call routing feature whereby a call agent immediately places a call to a specified destination when certain phones are taken off-hook.

Hewlett-Packard’s version of UNIX.

Hypertext Markup Language; a document type definition (DTD) used by web pages and browsers on the World Wide Web that tells a web browser how to render the content of a web page.

Hypertext Transfer Protocol; a method by which applications can exchange multimedia files on the World Wide Web.

A nexus in a network where data arriving from one endpoint can select multiple routes of egress.

Information Request Acknowledgement; a RAS message.

Intracluster Control Signaling; proprietary signaling that CallManager nodes in a cluster exchange to cooperatively manage calls.

Integrated Contact Distribution.

Intelligent Contact Manager; an application that manages distribution of voice, web, and e-mail across an enterprise of automatic call distribution (ACD), Private Branch Exchange (PBX), Interactive Voice Response (IVR), database, and desktop applications.

Internet Control Message Protocol; a message control and error reporting protocol carried over an IP network.

Information Element; an individual field in an ISDN message.

Internet Engineering Task Force; a standards body that issues recommended protocols for applications that interact over the Internet.

The link layer message that the ITU-T Q.921 standard defines for the purpose of encapsulating user data.

Internet Information Server; a Microsoft service designed to permit users to create and manage Internet services such as web servers.

Information Request N Acknowledgement; a RAS message.

Commonly used in the term intercluster trunks, this term refers to any interaction that occurs between CallManager nodes that are not members of the same cluster.

IP-based signaling and media control connections between clusters used for the purposes of call establishment. Intercluster trunks run a variant of the H.323 protocol.

An event that causes CallManager to cease collecting a dialing user’s dialed digits (and to route based on the entered digits) when CallManager detects that no digits have been entered for a specified period of time.

Internetwork Operating System; the operating system used by many Cisco routers and switches, including the gateways used by CallManager.

Internet Protocol; a method by which one computer can communicate packets of information to another computer on a network.

IP Contact Center; a software package that works with CallManager to perform call distribution and the management functions needed by call centers.

A set of protocols developed by the IETF to support the secure exchange of IP packets. IPSec both allows CallManager and the Cisco gateway to mutually authenticate each other and to ensure the privacy of the signaling stream via DES.

A business model whereby a service provider sells IP telephony connectivity to the PSTN to different subscribers.

The establishment of primarily voice, but also video and data communications over the same type of data network that makes up the Internet.

Internet Protocol/Videoconferencing; a family of Cisco videoconferencing devices.

Information Request; a RAS message that H.323 gatekeepers often use to monitor the status of H.323 terminals for which they maintain registrations.

Information Request Response; a RAS message that H.323 terminals send in response to a RAS Information Request message.

Integrated Services Digital Network; a digital circuit-switched-based telephony protocol that relies on interfaces that consist of a single D-channel for signaling and multiple B-channels for media.

Integrated Services User Part; a component of the SS7 telephony standard that handles call signaling. SS7 is a protocol widely used in the PSTN.

International Telecommunication Union Telecommunication Standardization Sector; the branch of an international standards body that develops and publishes standards related to telecommunications.

Interactive Voice Response; a voice application that provides a telephone user interface and that is capable of retrieving data and redirecting calls.

Interexchange carrier, or long distance company; a company whose chief responsibility is the interconnection of local exchange carriers.

The difference in time between a packet’s expected arrival time and the time the packet actually arrives. Also called variable delay.

Java Media Framework; an application programming interface (API) that enables audio, video, and other time-based media to be added to Java applications and applets.

Java Telephony Application Program Interface; an API that enables the development of Java applications that work with CallManager.

Java TAPI Service Provider; a library that makers of telephony systems provide to permit third parties to control the telephony system over JTAPI.

Kilobits per second.

Kilobytes per second.

Small-scale telephone system designed to handle telephone communications for a small office of 1 to 25 users.

Local-area network; a group of independent computers and network appliances within a small geographic area that access common resources and each other over communications protocols.

Local Access and Transport Area; in North America, geographical regions within the same LATA can generally place unmetered calls.

Liquid crystal display.

Location Confirm; an H.323 gatekeeper sends this RAS message, which provides the network address of an H.323 endpoint, to a requesting H.323 gatekeeper when the requesting H.323 gatekeeper needs to discover the endpoint’s network address.

Lightweight Directory Access Protocol; an API that defines a programming interface that can be used to access computer-based directories. LDAP directories are a specialized format of database that is often used to hold user information in large organizations.

Local exchange carrier, or local telephone company; a company whose chief responsibility is providing PSTN connectivity to residential and commercial subscribers.

Light emitting diode; a semiconductor device that emits light when an electric current passes through it.

Using established, possibly outdated, methods.

A logical entity on a phone capable of terminating calls; often associated with a particular button on a phone. Line appearances have addresses called DNs.

A network pathway that carries a streaming data connection between two endpoints.

A system of resolving conflicts between multiple matched dial patterns that prioritizes patterns that begin with the longest sequence of specific digits over patterns that begin with shorter sequences. With longest match routing, the dial string 1234 would select pattern 12XX instead of 1X34 in a configuration that included both patterns.

A signaling type most commonly used in residential service; when the phone goes off-hook, the circuit is closed, and the central office detects the change in current. The central office then inserts tone detectors to collect the digits, which are sent as tones on the wire.

Location Reject; an H.323 gatekeeper sends this RAS message to a requesting H.323 gatekeeper when it does not know the network address of the device that the requesting H.323 gatekeeper is seeking.

Location Request; an H.323 gatekeeper might send this RAS message to find out from other gatekeepers the network address associated with a particular E.164 or endpoint alias.

A device containing a network management agent implementation. The media server, MCS-7835-1000, is a managed device.

A mechanism commonly used by the call routing component of CallManager to enable you to change a number substantially while retaining some of the original number’s digits.

Megabits per second.

Megabytes per second.

Media Control Layer; the layer within CallManager responsible for coordinating the media control phase of call establishment.

Media Convergence Server; a Cisco-certified server that comes pre-installed with the components that make up Cisco IP Telephony.

Modify Connection; an MGCP message that the call agent sends to the gateway to modify the specified connection on an endpoint.

A one-way flow of media from one participant in a conversation to another. VoIP media streams are always encapsulated in RTP.

Media Gateway Controller; the call signaling and media control signaling intelligence for gateway devices.

Media Gateway Control Protocol; an IETF standard protocol, defined in RFCs 2705 and 3435 among others, that uses a text-based protocol to permit a Media Gateway Controller—a function that CallManager fulfills—to establish and tear down calls.

Management Information Base; a virtual information store that is used with network management protocol and network management application to provide information on a managed object.

Management Information Base; a single specification (an MIB), the union of all specifications implemented (the MIB), or the actual values of management information in a system.

Multipart Internet Mail Extensions; a set of methods described in RFC 2045 that allows binary information such as pictures and sounds to be converted to text and encoded in such a way that the recipient can reconstruct the original information.

Music On Hold; a CallManager feature that streams music to callers who have been placed on hold.

A file on a disk or a fixed device from which a source stream obtains the streaming data, which it provides to all connected streams.

A file on a disk or a fixed device from which a source obtains the streaming data that it provides to all connected streams.

MOH audio sources having the same filename and content. Usually spans multiple MOH servers. The MOH group is implemented as MRG in CallManager release 3.1.

One or more streams connected to an MOH audio source on an MOH server.

Software application that provides MOH audio sources and connects an MOH audio source to a number of streams.

Moving Picture Experts Group; a set of ISO and ITU standards for the compression of video.

Media Resource Group; a logical grouping of media servers that can be used to provide geographically specific, class of service, or class of user access to a set of media resources.

Media Resource Group List; a list that consists of prioritized MRGs. An application can select required media resources among the available ones according to the priority order defined in the MRGL.

Media Resource Manager; software component in CallManager that allocates and de-allocates media resources based on a provided MRGL.

Media termination point; a device that terminates a media stream for the purpose of allowing the stream to be redirected. CallManager can insert an MTP into a call to insulate endpoints from incompatibilities between each other’s media control processing, to provide DTMF relay, and to provide call progress tones.

Also multitenant. A type of CallManager installation in which one administrator manages a Cisco IP Communications network on behalf of a group of different enterprise or residential customers. This type of deployment is smaller in scale than IP Centrex.

Negative Acknowledge; a message sent by the remote end of a Transmission Control Protocol (TCP) connection that indicates failure of the connection’s establishment.

North American numbering plan; the set of valid dialable addresses on the North American PSTN.

The hold action that is initialized by system as the result of a feature invocation such as transfer or conference.

Network management station; a server where SNMP management applications run.

Servers in a CallManager cluster that are running the CallManager service.

Notify; an MGCP message indicating certain requested event has occurred on the gateway.

A repository of configuration data maintained by the Windows NT operating system. All applications on a computer can access the registry to store and retrieve configuration information.

A theory that suggests that to accurately encode an analog audio signal into a digital system and then accurately resynthesize the analog version, the frequency with which one must sample the signal must be at least twice the highest frequency present in the original analog signal.

In the context of SNMP, a data variable that represents some resource or other aspect of a managed device.

Defines a particular kind of managed object. The definition of an object type is therefore a syntactic description.

An 8-bit binary number corresponding to values 0 to 255 in the decimal system.

Open Database Connectivity; a vendor-independent standard that enables applications to interact with different databases.

The action whereby a user initiates a call or accepts an incoming call.

A term applied to calls between the enterprise and another telephone network (generally the PSTN).

The action whereby a user returns a station to an idle state.

A term applied to calls that are placed and received within the same enterprise.

One of a set of three tests (EXISTS, DOES-NOT-EXIST, ==) that route filters apply when determining which route patterns in the national numbering plan should be included as part of CallManager’s expansion of the @ wildcard.

A CallManager setting that dictates how long a media resource device, such as Cisco IP Voice Media Streaming App, waits until it tears down resources relating to a conversation. This happens when the Cisco IP Voice Media Streaming App has lost its connection to CallManager and it has detected no voice activity from an endpoint in the conversation.

Operating system; a set of services running on a hardware platform that provide other applications with access to the resources (such as processor, memory, network interfaces) that the hardware platform provides.

A high-pitched audio indication that CallManager applies during dialing to alert a calling user that the entered address may cause the call to route to a public network.

The process whereby CallManager collects dialed digits one at a time from a user. See also overlapped sending.

The process whereby CallManager collects dialed digits one at a time from a user.

The process whereby CallManager passes dialed digits from a calling user to switches in connected networks that actually manage the address.

Personal Assistant; an application that works with CallManager. This application is designed to permit a user to customize call forwarding behavior based on who is calling and to track a user down given multiple possible destinations.

A means of grouping the JTAPI functions used by applications.

A process of completing calls whereby a call agent manages call signaling and media control of two endpoints in a call but in which the media is streamed directly from one device to the other over a network of routers.

In a peer-to-peer network, a process of completing calls whereby two endpoints negotiate their call signaling, media control, and media session directly with each other over a network of routers.

Along with calling search spaces, a call routing concept that allows CallManager to provide individualized routing to users for purposes of routing by class of calling user, geographic location, or organization.

Private Branch Exchange; a small phone system located at a customer premise site. The PBX is used to supplement or replace functionality that might normally be provided by a central office (CO).

Personal computer.

Pulse Code Modulation; the standard for voice encoding in the circuit-switched world.

Protocol data unit; a unit of information that peer entities in a network exchange for control purposes.

A transmission and reception area for wireless devices less than 100 meters in radius.

Personal identification number.

Private Integrated Services Network Exchange; vendor call agents, such as a CallManager cluster or a PBX, in QSIG.

Background noise that resembles the background sounds from the current call. See also comfort noise.

Private Integrated Services Network; in QSIG, a privately owned network of PINXs.

Private Line Automatic Ringdown; see hotline.

Plain old telephone service.

To reset a device by interrupting and restoring power to the device.

Path replacement; a QSIG feature that eliminates hairpins by optimizing the call signaling and media path between two participants in a conversation.

The section of a route pattern that corresponds to all matched digits before the . wildcard’s position in the route pattern.

A field in an ISDN information element that specifically indicates whether a call recipient is permitted or forbidden from viewing the calling number.

Configuration settings that dictate whether the users involved in a call are permitted to view the calling or called name or number.

Primary Rate Interface; an ISDN interface containing 24 or 32 channels for the communication of media and signaling information.

The first line appearance on a station device.

A process whereby communications between network components is secured from the scrutiny of unauthorized intruders. Privacy prevents intruders from eavesdropping on conversations or capturing information such as dialed numbers from call attempts.

Public Safety Answering Point; an emergency response center dedicated specifically to handling emergency calls from subscribers on the PSTN. Emergency response centers have special facilities for contacting public safety and health officers.

Public Switched Telephone Network; the international phone system we all know and love. Typically displayed on block diagrams as a puffy, friendly looking cloud. Appearances can be deceiving.

The master database for CallManager.

Layer 2 protocol for ISDN telephony.

Layer 3 protocol for ISDN telephony.

Quick Buffer Encoding; commonly pronounced ″cube.″

Quarter Common Intermediate Format (QCIF).

Quality of service; the traffic management mechanisms of a distributed multimedia system that permit it to guarantee the transmission of coherent information. Such mechanisms include traffic classification, traffic prioritization, bandwidth management, and admissions control.

A messaging framework defined by ECMA and ISO that fosters feature transparency between PBXs.

The process of encapsulating the QSIG protocol within other call signaling protocols. H.323 defines a method (which CallManager supports) for tunneling QSIG in H.323 in Annex M1.

Redundant Array of Independent Disks; a device containing a set of disks that appears as a single disk to an operating system. RAIDs store copies of the same piece of data in different physical locations, thus providing security against component failure and possibly improving disk performance, because information can be written simultaneously to two different disks.

Registration, Admission, and Status; part of the ITU-T H.323 protocol that defines how H.323 endpoints and gatekeepers communicate.

The process whereby backup systems assume responsibility for providing network services if primary components fail or become unreachable.

A fast, cyclical tone that CallManager uses to indicate some sort of problem during call establishment.

In the context of AVVID XML Layer (AXL) application programming interface (API), requests are AXL API methods that allow a programmer to interact with and manipulate the CallManager database.

Request For Comments; a document that proposes Internet standards and is produced for public review by the Internet Engineering Task Force (IETF). RFCs that are accepted become official Internet standards.

Real-Time Information Server; a Cisco IP Communications service that collects serviceability information for multiple CallManager nodes in a cluster.

Resource Manager Essentials; a suite of web-based network management solutions for Cisco switches, access servers, and routers. Essential features include configuration management, change auditing, software image management, inventory, availability, and syslog analysis, while also allowing integration with other Cisco web management tools and third-party applications.

A textual clause composed of tags, operators, and values that CallManager uses to restrict which route patterns it includes when performing a macro expansion of the @ wildcard.

A CallManager feature that allows CallManager to search serially for and extend a call to an available gateway from among the gateways that the route list contains.

An expression that describes a numeric address (telephone number) or range of addresses; also, this expression as assigned to a gateway or route list.

Request Notify; a Media Gateway Control Protocol (MGCP) message that a call agent sends to a gateway to request the gateway to inform the call agent when a particular event (such as dialed digits) occurs.

Receiver Ready; an ITU-T Q.921 message that a message recipient sends when it is ready to receive a transmission from its peer.

Registration Request; a gatekeeper-enabled H.323 endpoint sends this RAS message to an H.323 gatekeeper when it wants the gatekeeper to maintain the address information (and possibly route calls for) the endpoint.

A recommendation published by Electronic Industries Association (EIA) that defines the physical and signaling characteristics of serial data communications.

Restart In Progress; a Media Control Gateway Protocol (MGCP) message that a gateway sends to a call agent to indicate that an endpoint or group of endpoints is being brought into or taken out of service.

Real-Time Control Protocol; Internet-standard protocol for the transport of control data relating to data transmitted by Real-Time Transport Protocol (RTP).

Real-Time Transport Protocol; Internet-standard protocol for the transport of real-time data, including audio and video.

Real-Time Streaming Protocol; a protocol used in streaming media systems that allows a client to remotely control a streaming media server, issuing VCR-like commands such as play and pause, and allowing time-based access to files on a server. Developed by the IETF and published in 1998 as RFC 2326.

Reliable User Datagram Protocol; a simple packet-based transport protocol that is layered on the UDP/IP protocols and provides reliable in-order delivery for virtual connections.

Syslog Analyzer; one of the CiscoWorks features that provides reports and analysis of syslog messages from the Cisco devices.

Set Asynchronous Balanced Mode (Extended); a link layer control message requesting the establishment of a connection over which numbered I-frames can be sent.

Skinny Client Control Protocol; a protocol used by CallManager and devices to provide signaling and media control functions for Cisco IP Phones.

System Diagnostic Interface; a trace interface that is used in CallManager.

Software Development Kit; a set of programming interfaces and documentation provided to programmers seeking to interface to a given operating system, application, or other product.

Signal Distribution Layer; an application framework that provides all of the components required to implement a state-machine-based application. It provides for creation of state machines and the interprocessor communication of signals between those state machines.

Specification and Description Language; an ITU-T language defined in specification Z.100 that describes a notation for state-machine-based systems.

Session Description Protocol; a protocol that allows SIP- and MGCP-based VoIP endpoints to negotiate IP addresses and ports for media communications using specific codecs.

Any line appearance on a station other than the first.

Settings for Cisco IP Communications services that take effect on a service-wide basis.

Skinny Gateway Control Protocol; a protocol used by devices to communicate with CallManager.

A directory number that appears on two or more devices. Phones with shared line appearances ring simultaneously when a call arrives at the shared directory number. A phone with a shared line appearance receives status information related to calls that other devices are managing on the shared directory number. (In CallManager, to be shared, directory numbers must also reside in the same partition.)

An agreed-upon set of rules that define the format of messages used to transmit information and commands between devices.

32-bit numbers that contain a 31-bit value plus a high-order sign bit.

The process whereby, to save network bandwidth, a voice-enabled IP device ceases transmitting media when the volume level of the speaker drops below a certain threshold.

One-way.

Session Initiation Protocol; an IETF standard related to HTTP and defined in RFC 3261 among many others that uses a text-based protocol for both signaling and, via SDP bodies, media control.

Simplified Message Desk Interface; an RS-232 protocol that can be used to integrate a voice mail system with a PBX. CallManager provides an interface to voice mail systems with the Cisco Messaging Interface service, also known as CMI.

Structure of Management Information; specifications that define the model of management information, the allowed data types, and the rules for specifying classes (or types) of management information.

Simple Network Management Protocol; a protocol designed to permit monitoring and management of devices on a computer network.

Context-sensitive digital display buttons on the bottom row of the display of XML-capable Cisco IP Phones, such as models 7905, 7912, 7920, 7940, 7941, 7960, 7961, 7970, 7971, and 7985.

A server-based conference mixer capable of mixing G.711 and wideband audio streams and rebroadcasting them to conference participants.

A connection point on an MOH server where streams can be connected. It provides the audio-streaming data to all connected streams.

Structured Query Language; a standard language defined to permit reading from and writing to databases.

Signaling System 7; a protocol used on the Public Switched Telephone Network (PSTN) that uses a separate packet-switched network for the carriage of signaling information between switches in the PSTN.

Small event-driven processes within the layers of the CallManager architecture that handle small bits of the responsibility of placing calls in a CallManager network. These small state-machine tasks are managed by the SDL application engine.

Any device that provides a user with a direct interface to a voice network.

An initial sequence of digits used to direct calls to a particular set of gateways.

A one-way, active media session connected through a simplex logical channel from an MOH server to a device.

One or more duplicate databases serving the CallManager system. Subscriber databases are updated with information from the Publisher database.

A user of a (usually public) telephone network.

A framing strategy that groups frames of audio information into groups of 12.

The process whereby devices unregister with one CallManager node and reregister with a higher-priority CallManager node.

A process whereby where a secondary call agent can assume control of the call signaling and media control for a call that was earlier controlled by a different call agent.

An ITU standard composed of a suite of communication and application protocols. Using these protocols, developers can create compatible products and services for real-time, multipoint data connections and conferencing.

A digital trunk interface that provides twenty-four 64-kbps timeslots for a total of 1.544 Mbps of bandwidth.

A digital trunk interface that provides 44.736 Mbps of bandwidth.

Cisco Technical Assistance Center; a customer support organization.

A text string that characterizes a meaningful portion of one or more route patterns in a dial plan file. Route filters rely on tags to classify numbers within a dial plan.

Telephony Application Programming Interface; a Microsoft API that permits programmers to create telephony applications on Windows systems.

Cisco Telephony Call Dispatcher Service; the server-side process from which Cisco WebAttendant clients obtain their call control services.

Transmission Control Protocol; a connection-oriented protocol that provides for the reliable end-to-end, ordered delivery of IP packets.

Time division multiplexing; a method of transporting information for multiple endpoints across a single interface that relies on assigning each endpoint a specific window of time when it has exclusive access to the interface.

A routing-related setting on the gatekeeper configuration that allows a gatekeeper to differentiate between groups of endpoints in the same zone.

Trivial File Transfer Protocol; a User Datagram Protocol (UDP)-based protocol that permits the transmission of files between network devices.

A method of application control by which the application controls one or more endpoints and simultaneously maintains a view of all controlled endpoints.

Telealue, a geographical routing prefix in the Finnish national numbering plan.

A configuration whereby an enterprise routes calls between geographical regions over its own IP network instead of the PSTN, thereby avoiding any charges that the PSTN levies for placing the call.

Type of service; a method of classifying the data that a network routes to provide preferential packet routing treatment to data related to certain types of media: voice, data, and video, for example.

The process of assigning preferential routing treatment to media streams based on the type of information they contain.

To convert a voice data stream from one codec type to another codec type.

A hardware or software device that provides a means of allowing devices that do not have a matching set of capabilities for the allowed bandwidth to communicate. Transcoders convert one media stream type into a different media stream type to allow devices to communicate.

A CallManager call routing feature that permits you to define aliases for route patterns.

A trap is an unsolicited message sent by an agent to a management station in an asynchronous manner. The purpose is to notify the management station of some unusual event. The traps are sent to trap-receiving hosts configured in the Windows 2000 SNMP Service. With this enhancement, network management applications such as Voice Health Manager (VHM) can gather more data that can be used for fault management and analysis purpose.

A circuit between a station and the network that serves it or between two networks.

TAPI Service Provider or Telephony Service Provider; a library that makers of telephony systems provide to permit third parties to control the telephony system over Microsoft’s Telephony Application Program Interface (TAPI).

Tab-separated values; a file format in which individual data fields of a record are separated by a tab character and records are separated by new lines.

Time-to-live; a piece of information embedded in broadcast and multicast packets that dictates how many router hops a packet is permitted to traverse.

User agent; in SIP, an entity that includes the functions of both a UAC and a UAS.

User agent client; the originator of a SIP method.

User agent server; the originator of SIP responses.

User Datagram Protocol.

Unified messaging system; a system that provides a unified way of accessing voice mail, e-mail, and fax.

A hardware or software device that receives multiple media streams from parties on a conference, sums the information contained within, and rebroadcasts the summed information to each conference participant.

32-bit numbers that contain a 32-bit value that is assumed to be a positive number.

Uniform Resource Identifier; an Internet naming format. URLs are a type of URI.

Unregister reject; an H.323 gatekeeper sends this RAS message to an H.323 endpoint when it denies the endpoint’s request that the gatekeeper purge registration information related to the endpoint.

Uniform Resource Locator; an Internet addressing format.

Unregistration Request; a gatekeeper-enabled H.323 endpoint sends this RAS message to an H.323 gatekeeper to ask the gatekeeper to purge registration information related to the endpoint.

A person or software application that makes use of a system.

A hold action that is initialized by an end user who presses the hold button on a phone.

User-User Information Element; a field defined by ITU-T Q.931. H.323 messages use this field to encapsulate H.323-specific values.

In the H.225 protocol, v2 refers to version 2.

Voice activity detection; see silence suppression.

Variable binding; in Simple Network Management Protocol (SNMP), a pairing of an object instance name and its associated value.

Video Coding Experts Group.

Voice Health Manager; a CiscoWorks application that provides proactive fault management and root cause analysis for Cisco IP Communications system. It was also previously known as Voice Health and Fault Manager (VHFM).

Voice interface cards; typically small trunk interface modules that are inserted into IOS gateways to allow for OffNet communication.

See codec.

A compressed stream of data packets of a specific format supported by a specific video codec. This series of data packets is then routed to the other endpoint through a previously established logical channel.

See codec.

Voice over IP; the process of routing voice communications over a network running Internet Protocol.

Wide-area network.

Elements within route patterns that describe a range of matching digits, cause a previous wildcard to match multiple digits, delimit portions of the route pattern, or direct CallManager to perform a macro expansion.